This invention relates to a connector used in an electronic equipment such as a cellular phone, and particularly to a right angle-type spring connector mounted horizontally on a board.
A cellular phone contains a battery as a main power source, and this battery and an equipment body are electrically connected together via a spring connector mounted on a printed wiring board of the equipment body.
With the achievement of a low profile design of cellular phones in recent years, there has been an increasing demand for a low-profile design of the spring connector.
A spring connector 100 of the related art is shown in FIGS. 10 and 11.
The spring connector 100 of the related art is surface mounted on a board 200, and in FIG. 10, 60 denotes a resin-made insulative housing, 70 denotes a tube made of an electrically-conductive material, 30 denotes a pin, and 40 denotes a spring. Within the housing 60, the plurality of pins 30 having electrical conductivity and serving as contacts are received, together with the respective springs 40, in the respective tubes 70.
As shown in FIG. 10, the pin 30 is urged by the spring 40, and is held in such a condition that its distal end is projected from an open end portion of the tube 70. After the spring 40 and the pin 30 are inserted into the tube 70, the open end portion of the tube 70 from which the pin 30 projects is press-deformed. Therefore, the pin 30 can slide within the tube 70, but will not escape from the tube 70 to the exterior.
Hole portions 61 for the insertion and holding of the respective tubes 70 are provided in the housing 60, and the tube 70 in which the pin 30 and the spring 40 are received and held therein is inserted into this hole portion 61. A holding portion 62 is provided at the hole portion 61, and is formed such that it projects radially inwardly in the hole portion 61. A diameter (hole diameter) of this holding portion 62 is smaller than an outer diameter of a receiving portion 71 of the tube 70, which is a portion on this tube for receiving the holding portion 62 when the tube 70 is inserted into the hole portion 61. Therefore, the tube 70 is press-fitted into the hole portion 61 of the housing 60, and is held therein. FIG. 11 is a transverse cross-sectional view showing this holding portion 62 and the receiving portion 71. As shown in FIG. 11, the holding portion 62 is so formed as to cover the receiving portion 71 in a peripheral direction so that the tube 70 will not fall from the housing 60 in a downward direction.
In the spring connector 100 of the related art, the following construction has been introduced in order to achieve its low-profile design.
Slits 63 communicating respectively with the hole portions 61 are formed in a lower portion of the housing 60, and the tube 70 inserted into the hole portion 61 is exposed to the exterior of the housing 60 through this slit 63. A mounting portion 72 for electrical connection to the board 200 is formed on an outer peripheral surface of the tube 70, and the mounting portion 72 exposed from the slit 63 is connected by soldering or the like to a land (not shown) formed on the board 200. Therefore, the height of the spring connector 100 on the board 200 is reduced in an amount corresponding to a saved lower portion of the housing 60 that is eliminated by such construction.
However, the following problems may occur in the spring connector 100 of the related art.
In the press-fit holding structure in which the diameter of the holding portion 62 of the housing 60 is set to a size smaller than the outer diameter of the receiving portion 71 of the tube 70, thereby holding the tube 70, deformation as shown in FIG. 11 develops in the housing 60 because of the existence of the slits 63 formed in the lower portion of the housing 60 and of stresses produced by the press-fitting. Namely, when the stresses are applied to an upper portion of the housing 60, which also has the slits 63 in its lower portion, this results in a problem in that the lower portions of the slits 63 are widened, so that the whole of the housing 60 is warped upwardly.
On the other hand, when the housing 60 holding the tubes 70 is solder mounted on the board 200, solder is coated on the lands on the board 200, and thereafter the housing 60 is mounted on the board 200, with the mounting portions 72 of the tubes 70 being exposed from the respective slits 63, and the soldering is then effected by heating. Accordingly, there is also a fear that the housing 60 may be further deformed by the influence of heat during the heating.
With the thus deformed housing 60, its stable electrical connection to the board 200 can not be obtained. To avoid this deformation, it is necessary to thicken the upper portion of the housing 60 (the portion disposed above the hole portions 61), and therefore this leads to a drawback in that the overall height of the spring connector becomes large.